title: Prevalence and clonal analysis of Porphyromonas gingivalis in primary endodontic infections.
abstract: This study investigated the prevalence of Porphyromonas gingivalis in 62 teeth with primary endodontic infections by using a species-specific 16S rRNA gene-based nested polymerase chain reaction assay. P. gingivalis isolates recovered from 2 infected root canals were also analyzed for clonal diversity by using arbitrarily primed PCR. Overall, P. gingivalis was found in 48% of the samples. This species was specifically detected in 36% of canals of teeth with chronic apical periodontitis, in 46% of the cases of acute apical periodontitis, and in 67% of acute apical abscesses. P. gingivalis was significantly more frequent in abscess aspirates than in canals of teeth with chronic apical periodontitis (P < .05). Typing of colonies retrieved from 2 infected canals revealed 2 clones per individual. These findings confirmed that P. gingivalis can be an important endodontic pathogen, mostly associated with acute abscesses, and demonstrated that different clonal types of this species can colonize the root canal in the same individual.
authors.affiliation: Department of Endodontics and Molecular Microbiology, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, Brazil. Electronic address: jf_siqueira@yahoo.com.
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
authors.affiliation: Department of Endodontics and Molecular Microbiology, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
authors.forename: Isabela N
authors.initials: IN
authors.lastname: Rôças
authors.affiliation: Institute of Microbiology Prof. Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Marlei G
authors.initials: MG
authors.lastname: Silva
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D014644:Genetic Variation; D006801:Humans; D008875:Middle Aged; D010482:Periapical Abscess / Q000382:microbiology*; D010484:Periapical Granuloma / Q000382:microbiology; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000235:genetics* / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014774:Virulence; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S